Was looking at an plane some weeks ago and noticed this on the beige sludge that looks like oil mixed with water.
This was after a 45min flight.
I guess it’s not normal and could be an issue.
Common on smaller Conti motors, but not in this quantity… this extreme accumulation is probably caused by lack of maintenance, such as cleaning the air/oil separator if installed, replacing the oil on a 4 months/25/50hr schedule, or just flying long enough for the oil to reach its nominal T of around 180°F and at least 1hr flight time for the condensed moisture to evaporate.
A fully blocked breather tube can have dire consequences, such as a blown front crankshaft seal leading to a total oil loss…
Dan wrote:
A fully blocked breather tube can have dire consequences, such as a blown front crankshaft seal leading to a total oil loss…
.. or an in-flight engine shutdown (one gentleman had it on a twin…).
Exxon Elite oil used to produce this sludge, but nothing like as bad as these photos.
Not sure what Oil he uses, just know it’s a straight XX oil.
I walked away from this aircraft, not just because of above but there was other signs that I didn’t like.
Corrosion signs here and there, landing gear struts that leaked oil, flaking/cracks in paint.
Owner said he maintained his aircraft very well…
Fairly typical tired aircraft, maintained by a fairly typical company, which has what I might call an “enthusiastic” paint job some years before.
Not as bad as this but I believe same type. The Arrow attracts this sort of operation because it is the cheapest retractable you can buy.
FWIW you can also get sludge if you do short flights e.g. < 30 mins airborne time. The oil never gets hot enough to boil off the water. But this case is really bad.
Good decision.
When you see this kind of sludge, time to change out oil, we dont know whats in it now. Case is not breathing, time to look at the breather tube, make sure it is clean and clear, also adding insulation to the tube will help As mentioned, we also dont know if the oil temps are normal. All this play in what the phots show. Some planes are critical on the location of the outlet of the tube, some are inside the cowl, some are just on the outside to have slipstreams help evacuate the tube. MM may give insight on this. carl
Not abnormal to see on a lot of continentals, especially on the top cap fill pipes. They just never get hot enought to boil off mix. ( in cooler wx)
